It is known that chip breaking and chip removal during cutting can be facilitated by the provision of recesses in the rake face (DE-C-28 40 610). The chip obtains there during the cutting operation a wave-like structure and thereby a greater stiffness which is necessary for easy breaking. Especially for drilling, small, short broken chips are important for undisturbed stress relief. For this purpose suitable deformation of the stiffened chip, which leads to reliable chip breaking, is additionally required.
Starting with this, the present invention has the object to improve the known cutting insert of the kind. described above in such a way that during machining the formation of small, short broken chips is facilitated.